fix(user-select): move addUserSelectStyles from handleDragStart to ha…

[fxxjdedd]

If it's just a simple click, don't modify the DOM.

[STRML]

This will add the styles multiple times, I doubt that is desired.

[fxxjdedd]

This will add the styles multiple times, I doubt that is desired.

This is indeed a problem, Maybe we need an extra if in handledrag.

However, it is necessary not to add styles when clicking. Because in actual development, we do have two different types of logic: click and drag. When there are too many heavy GridItems, click can cause some performance problems

[fxxjdedd]

@STRML
Hello,
I found that addClassName already has logic to avoid duplicate classes. However, I can add another hasUserSelectStyles judgment if necessary.